This invention relates generally to emergency illuminating devices intended for use mainly in aircraft and adapted to operate under serious impact or distress conditions resulting from crashing of the aircraft or in the case of fire or explosions. It should be understood, however, that the principles of the invention can be applied to other structures such as hotels or public buildings, as well as including audible or tactile discernible means, in time of emergency such as fires or explosions.
In most aircraft, or other public structures, the means for illumination is generally located overhead, as are the emergency exit signs. It has been noted that in most crashes or fires large amounts of smoke or other small particulate matter is suspended in the air which makes the illumination and exit signs virtually ineffective. Additionally, confusion and panic tend to reign supreme and instructions given by the flight crew relative to location of emergency exits is forgotten or misinterpreted.
It is paramount that an illuminating device that locates the emergency exits of aircraft be designed to operate instantly in response to impact, temperature elevations, and/or smoke. Every second that can be saved in removing the occupants from the environment is important since delays can result in serious injury, a matter of life or death.
In the past, most attempts have been to provide high intensity lights, adjacent exits, that are activated either upon impact or upon an excessive deceleration of the aircraft. These devices do not provide specific guidance to the passengers other than to merely locate a particular exit and, again, because of their nature, are generally located at an elevated position subject to camouflage by smoke or other particulate matter. Such devices can be found in U.S. Pat. No. 3,411,131 issued Nov. 12, 1968 and No. 3,428,941 issued Feb. 18, 1969 both being in the name of B. V. Hewes.
The transmission of light by edge lighted plastic materials has been utilized in environments other than those contemplated by the present invention, for example see U.S. Pat. No. 2,672,551 issued Mar. 16, 1954 in the name of D. H. Hale et al; No. 2,699,141 issued Jan. 11, 1955 in the name of E. O. Gaguski; No. 3,144,643 issued Aug. 11, 1964 in the name of P. H. A. Andersson; and No. 3,169,506 issued Feb. 16, 1965 in the name of W. J. Morris. None of these devices teach or suggest their use with sequentially pulsed light sources for emergency guidance systems.